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March 29, 2016

Dear Christians: Answers to Questions for Atheists, Part XII

Today, we're in Part XII of my series responding to questions for atheists, and I'm excited to be talking about evolution.

I was raised a young earth creationist. We were taught that Genesis is a literal rendering of the events that led to the creation of our world, and that the world was literally about 6,000 years old. In seventh and eighth grade, I attended a small Christian school run by our church, and an entire chapter of our science book was devoted to refuting evolution. Throughout my time in the church, I attended apologetics lectures designed to assure me that evolution was wrong and prepare me to refute it myself.

There were two arguments in particular that have always stuck with me. The first is the idea that Charles Darwin was not a scientist because he was no good at math...? Of course, I did not hear that same criticism of Michael Faraday, a Christian scientist whose lack of schooling also left him with a serious gap in mathematical knowledge. Perhaps luckily, I don't typically see this argument anymore. I'm not sure if it has fallen out of favor or if it was just a function of the extreme conservative rhetoric and A Beka curriculum we were studying under.

The second is the idea that okay, yeah, sure, microevolution happens. Species adapt. That's smart! God designed it that way so they would be flexible! But macroevolution? UH UH. NO WAY, DUDES. Speciation is a myth. NO ONE HAS EVER SEEN IT, YOU KNOW.

In today's section on Evolution, we're going to see the macro versus micro argument make appearance, along with a few other arguments that, I must say, I'd never seen before. Let's take a look, shall we?

EVOLUTION

1. Is the theory of evolution THE refutation to divine creation? Why?

No. It's not the refutation to anything--it's fact. It wasn't discovered to refute divine creation. It was discovered because it is a natural process.

2. Is the theory of macro-evolution a scientific fact? How do you know?

For me, though, the most compelling evidence of "macroevolution" is that we share DNA with oak trees. Bananas. There's really no reason for it except that DNA is a hereditary link to long dead ancestors that we shared with pretty much every form of life on this planet.

3. Aren’t our genetic components exactly the same as mice, not apes? Wouldn’t that make our common ancestor more likely to be a mouse based on evolutionary theory?

On average, the protein-coding regions of the mouse and human genomes are 85 percent identical; some genes are 99 percent identical while others are only 60 percent identical. These regions are evolutionarily conserved because they are required for function. In contrast, the non-coding regions are much less similar (only 50 percent or less). Therefore, when one compares the same DNA region from human and mouse, the functional elements clearly stand out because of their greater similarity. Scientists have developed computer software that automatically aligns human and mouse sequences making the protein-coding and regulatory regions obvious.

So, no. We're not genetically the same as mice...? I'm assuming that's what this question is asking, because the wording is weird for me.

As for great apes, we're anywhere from 5% to 1.2% genetically distinct from African great apes, depending on how you calculate the difference.

But let's talk about the basic premise of this question: If we are genetically similar to mice, we must be related to them but not apes. There's a serious issue in here. I am not sure if it's entirely accurate, but I want to label this a false equivalency. It MUST be one or the other...except no, it doesn't have to be one or the other. In reality, because we ALL--mice, humans, great apes--share a common ancestor, we ALL share some genetic components.

This is a basic misunderstanding of evolutionary theory. And it's...it's really laughable.

4. In relation to all other ‘descendents’, why are the following ‘Cultural Big Bangs’ unique only to the human species?

And that's not the only issue with this question. I'm not sure where this idea that we're the only species to exhibit cultural behaviors comes from, but it's patently false. Here's another example:

One of the clearest places to look for clues of our cultural capacity is in one of our closest relatives: chimpanzees. Researchers have observed chimps performing certain behaviors that differ between populations and that seem to be passed by social learning, just as they are in human cultures.

For instance, some chimp populations have invented a means of cracking open a nutritious but hard-shelled nut, while other communities haven't.

Now, as the piece I've linked goes on to say, more research is needed to determine whether these are actual learned traditions or just independently. There's also orcas:

Orcas have evolved complex culture: a suite of behaviors animals learn from one another. They communicate with distinctive calls and whistles. They can live 60 years or more, and they stay in tightknit matrilineal groups led by older females that model specific behaviors to younger animals. Scientists have found increasing evidence that culture shapes what and how orcas eat, what they do for fun, even their choice of mates. Culture, says Hal Whitehead of Dalhousie University in Halifax, Nova Scotia, “may be very important to them.”

One of the biggest advantages that we have in the way of cultural adaptation is language. Our ability to use language significantly improves the ways in which we transmit culture. It even changes our ability to think about things.

We can observe the importance of language to the application of human intelligence in a variety of ways, but one of my favorites is the way that language can influence saving behaviors. Economist Keith Chen examined the importance of strong versus weak future tenses on human saving behavior and found that when a language has a weak future tense, saving becomes more prominent. This is because there is not such a large distinction between now and the future. Imagine the difference between saying, "I am going to the store today," versus "I will go to the store tomorrow." One conveys a sense of action, while the other relays a sense of space. Without those differentiations, though, tomorrow and today are not so removed from each other.

Language shapes the way we view the world. It enables us to think about abstract concepts in a way that species without language cannot.

Using a mathematical model, Dr Thomas Scott-Phillips and his colleagues, show that the evolution of combinatorial signals, in which two or more signals are combined together, and which is crucial to the expressive power of human language, is in general very unlikely to occur, unless a species has some particular psychological mechanisms. Humans, and probably no other species, have these, and this may explain why only humans have language.

Above and beyond that, the apparent uniqueness of our ability to develop and use language isn't a critique of evolution like this question seems to suggest. Rather, it's evidence of precisely what evolutionary theory is based on: random mutations that accrue regardless of objective usefulness.

Think of it this way. The ability to create language is an amazing adaptation. It's made possible by changes in our brains themselves, changes that accrued as random mutations. It would be so useful for other species to also have this mutation--and yet none of them do.

But maybe you were implying something else. Maybe you are suggesting that intelligence seems like a very useful thing, and that it seems intuitive that many things would have also evolved this useful characteristic. For example: wings are useful! And many things evolved wings: insect, birds, some weird kinds of lizards, and so on. Why isn’t it also like that for intelligence?

To answer this, I have to go back to one of the basic principles that I described in my earlier response to you: evolution actually does not have a bias toward evolving things that are particularly useful in a general sense. That is a misconception about how evolution works. Evolution is based on the idea that differences happen randomly, and when a random difference is especially harmful, it is weeded out. This leaves the next generation that is slightly different in its overall average composition than the earlier generation.

Stevens makes several good points, and his example of giraffes and neck length is spot on in my opinion, but I'm not going to reproduce them all here--I strongly encourage everyone to visit the link. But I do want to share one final quote:

How does this relate to intelligence?

Intelligence evolved in the same way. Gradually, over time, there were certain characteristics that actually were relevant to survival. The environment was set up so that our ancestors who could use signs and symbols, for example, were able to survive and reproduce better than those who couldn’t. So as a result, those traits spread throughout the population.

But different animals live in different environments, and in different niches. A lion is the king of its domain: at the top of the food chain. If one lion has a better memory than another, or can think faster than another, that doesn’t necessarily mean it will be able to survive better or get more food. It is like the short-necked giraffe in a land where food is plentiful and low to the ground: there is no selection that “weeds out” low extremes of the trait. So if there is nothing that weeds out lions with mediocre memories, then there is no reason for the average power of a lion’s memory to grow. If there is nothing that weeds out lions who can’t solve puzzles, then there is no reason for the ability of lions to solve puzzles to improve.

Intelligence will only evolve when there is a specific problem that it solves. It will only evolve when something in the environment is killing off the animals that are on the “low end” of the population.

Evolution doesn't care how useful an adaptation is in the abstract (it does, in fact, care about anything at all, because it's a process and not an animate being). It's all about what's specific to an environment any given point. Those environmental pressures will be what encourages evolution in a particular direction, via natural selection.

And not every offspring of an individual coming out of the same environment will require the same adaptations to survive. Giraffes and zebras share the same environment; they each have specific adaptations that allow them to survive in that environment. Indeed, in my opinion (and I'm not going to bother googling this, so someone feel free to correct me if I'm mistaken), having a variety of adaptations would be helpful for species. Different adaptations would allow them to fill different environmental niches, and, in the large scale, contribute to a well-balanced ecosystem.

*****

I always try to wrap up with some advice, so here's what I've got: stop trying to make this a contest.

Evolution was not conceived as a way to get rid of God. Darwin himself was a believer at the time. He wasn't looking for evidence that there was no god. He was simply observing natural phenomena and coming up with explanations for it--and the explanation has stood the test of time.

Evolution isn't a "refutation" of creation. Evolution is an explanation for observations of what's happening all around us, all the time. It's supported by cross-disciplinary evidence. Predictions made by Darwin in his initial works on the subject are still ringing true (although others have been refined or refuted, because that's what science does).

If your religion can't accept reality...maybe it's time to consider a new religion. Or none at all. I'm just sayin'.